Insights into the Genetics and Signaling Pathways in Maturity-Onset Diabetes of the Young

Publisher Copyright: © 2022 by the authors.Diabetes Mellitus (DM) is a complex disease with a significant impact in today’s world. Studies have emphasized the crucial role of genetics in DM, unraveling the distinction of monogenic diabetes from the most common types that have been recognized over the years, such as type 1 diabetes (T1DM) and type 2 diabetes (T2DM). A literature search was carried out to scrutinize the subtypes of maturity-onset diabetes of the young (MODY), as well as the connection between the recognized genetic and molecular mechanisms responsible for such phenotypes. Thus far, 14 subtypes of MODY have been identified. Here, the authors review the pathophysiological and molecular pathways in which monogenic diabetes genes are involved. Despite being estimated to affect approximately 2% of all T2DM patients in Europe, the exact prevalence of MODY is still unknown, enhancing the need for research focused on biomarkers. Due to its impact in personalized medicine, a follow-up of associated complications, and genetic implications for siblings and offspring of affected individuals, it is imperative to diagnose the monogenic forms of DM accurately. Currently, advances in the genetics field has allowed for the recognition of new DM subtypes, which until now were considered to be slight variations of the typical forms. New molecular insights can define therapeutic strategies, aiming for the prevention, correction, or at least delay of β-cell dysfunction. Thus, it is imperative to act in the close interaction between genetics and clinical manifestations to improve diagnosis and individualize treatment.publishersversionpublishe

Doença de Machado-Joseph à procura de biomarcadores moleculares

A secção Biologia é coordenada pelo Professor Universitário Armindo Rodrigues.As doenças neurodegenerativas, das quais a doença de Parkinson ou a doença de Alzheimer são exemplos paradigmáticos, constituem patologias cuja prevalência tende a aumentar, dada a tendência global das populações para o envelhecimento. Tendo por base alterações celulares complexas, estas doenças colocam desafios ao nível do diagnostico e do tratamento, que refletem, em parte, a dificuldade em “exportar” o conhecimento proveniente da investigação, colocando-o ao serviço dos doentes (a chamada investigação bench-to-bedside). De entre as doenças neurodegenerativas, um subgrupo tem natureza hereditária. A doença de Machado-Joseph (DMJ) faz parte desse subgrupo. Trata-se de uma doença complexa, na qual vários sistemas neurológicos podem estar afetados, que se carateriza, em termos muito genéricos, pela incoordenação de movimentos, nomeadamente ao nível da marcha. Sob o ponto de vista genético, a DMJ e causada por um gene localizado no cromossoma 14; a doença, de início na idade adulta, e dominante, o que significa que basta uma dose do gene mutado (alterado), herdado a partir do pai ou da mãe, para fazer surgir a patologia. […].info:eu-repo/semantics/publishedVersio

Whole-genome-wide linkage and IBS/IBD studies

Twelve families with exuberant and early-onset calcium pyrophosphate dehydrate chondrocalcinosis (CC) and diffuse idiopathic skeletal hyperostosis (DISH), hereafter designated DISH/CC, were identified in Terceira Island, the Azores, Portugal. Ninety-two (92) individuals from these families were selected for whole-genome-wide linkage analysis. An identity-by-descent (IBD) analysis was performed in 10 individuals from 5 of the investigated pedigrees. The chromosome area with the maximal logarithm of the odds score (1.32; P=0.007) was not identified using the IBD/identity-by-state (IBS) analysis; therefore, it was not investigated further. From the IBD/IBS analysis, two candidate genes, LEMD3 and RSPO4, were identified and sequenced. Nine genetic variants were identified in the RSPO4 gene; one regulatory variant (rs146447064) was significantly more frequent in control individuals than in DISH/CC patients (P=0.03). Four variants were identified in LEMD3, and the rs201930700 variant was further investigated using segregation analysis. None of the genetic variants in RSPO4 or LEMD3 segregated within the studied families. Therefore, although a major genetic effect was shown to determine DISH/CC occurrence within these families, the specific genetic variants involved were not identified.publishersversionpublishe

Urolithiasis Bioresource

Urolithiasis is frequent and raises significant health care burden in a working-age population. Its prevalence, in the Azores archipelago, is currently unknown but it is thought to be higher than the overall estimated prevalence. The Azores Biobank (AZORBIO) Urolithiasis samples have been collected in accordance with standard operation procedures (SOPs) to ensure high quality. Each donor provided 30 ml whole blood and 9 ml of urine. If possible, we preferred blood collected from fasting individuals and first morning urine samples. Aliquots of plasma, serum, DNA, RNA and urine, are stored at -80°C freezers. This collection of samples, and data, will be used to investigate the genetic and/or environmental risk factors associated with the disease in this geographical area.</p

Novel candidate blood-based transcriptional biomarkers of Machado-Joseph disease

BACKGROUND: Machado-Joseph disease (or spinocerebellar ataxia type 3) is a late-onset polyglutamine neurodegenerative disorder caused by a mutation in the ATXN3 gene, which encodes for the ubiquitously expressed protein ataxin-3. Previous studies on cell and animal models have suggested that mutated ataxin-3 is involved in transcriptional dysregulation. Starting with a whole-transcriptome profiling of peripheral blood samples from patients and controls, we aimed to confirm abnormal expression profiles in Machado-Joseph disease and to identify promising up-regulated genes as potential candidate biomarkers of disease status. METHODS: The Illumina Human V4-HT12 array was used to measure transcriptome-wide gene expression in peripheral blood samples from 12 patients and 12 controls. Technical validation and validation in an independent set of samples were performed by quantitative real-time polymerase chain reaction (PCR). RESULTS: Based on the results from the microarray, twenty six genes, found to be up-regulated in patients, were selected for technical validation by quantitative real-time PCR (validation rate of 81% for the up-regulation trend). Fourteen of these were further tested in an independent set of 42 patients and 35 controls; 10 genes maintained the up-regulation trend (FCGR3B, CSR2RA, CLC, TNFSF14, SLA, P2RY13, FPR2, SELPLG, YIPF6, and GPR96); FCGR3B, P2RY13, and SELPLG were significantly up-regulated in patients when compared with controls. CONCLUSIONS: Our findings support the hypothesis that mutated ataxin-3 is associated with transcription dysregulation, detectable in peripheral blood cells. Furthermore, this is the first report suggesting a pool of up-regulated genes in Machado-Joseph disease that may have the potential to be used for fine phenotyping of this disease.Fundação para a Ciência e a Tecnologia (FCT) - project FCOMP-01-0124-FEDER-028753 (PTDC/DTP/PIC/0370/2012)Operational Competitiveness Programme—COMPETEUK Medical Research Council (MRC)Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BPD/33611/2009Fundo Regional para a Ciência (FRC), Governo dos Açores - M3.1.2/F/006/2011; M3.1.7/F/031/2011 ; M3.1.3/F/004/200

Evaluation of two methods for computational HLA haplotypes inference using a real dataset

<p>Abstract</p> <p>Background</p> <p>HLA haplotype analysis has been used in population genetics and in the investigation of disease-susceptibility locus, due to its high polymorphism. Several methods for inferring haplotype genotypic data have been proposed, but it is unclear how accurate each of the methods is or which method is superior. The accuracy of two of the leading methods of computational haplotype inference – Expectation-Maximization algorithm based (implemented in Arlequin V3.0) and Bayesian algorithm based (implemented in PHASE V2.1.1) – was compared using a set of 122 HLA haplotypes (A-B-Cw-DQB1-DRB1) determined through direct counting. The accuracy was measured with the Mean Squared Error (<it>MSE</it>), Similarity Index (<it>I</it>_<it>F</it>) and Haplotype Identification Index (<it>I</it>_<it>H</it>).</p> <p>Results</p> <p>None of the methods inferred all of the known haplotypes and some differences were observed in the accuracy of the two methods in terms of both haplotype determination and haplotype frequencies estimation. Working with haplotypes composed by low polymorphic sites, present in more than one individual, increased the confidence in the assignment of haplotypes and in the estimation of the haplotype frequencies generated by both programs.</p> <p>Conclusion</p> <p>The PHASE v2.1.1 implemented method had the best overall performance both in haplotype construction and frequency calculation, although the differences between the two methods were insubstantial. To our knowledge this was the first work aiming to test statistical methods using real haplotypic data from the HLA region.</p